Strong Wind Events Across Greenland's Coast and their Influences on the Ice Sheet, Sea Ice, and Ocean

Marilena Oltmanns, Ph.D., 2015Fiamma Straneo , Advisor

Greenland’s margins that are adjacent to the subpolar North Atlantic and Nordic Seas are characterized by a large land-sea temperature contrast during winter. Therefore, winds perpendicular to the coast can result in significant surface heat fluxes over the ice sheet and the ocean.

This thesis includes the first comprehensive study of the characteristics, dynamics and impacts of these winds. Using a variety of data and model products, it is shown that high-speed wind events across the coast result from the interaction of the large-scale atmosphere with Greenland’s high elevation. Onshore winds can cause increased melting, and offshore winds drive large heat losses over major ocean convection regions. Strong offshore winds across the southeast coast, in particular, are unique because the flow is funneled from a large area of the ice sheet into the narrow valley of Ammassalik, where winds can reach hurricane intensity. Small-scale mountain wave dynamics contribute to the acceleration of the downslope winds in this region. These winds advect sea ice offshore and out of a major glacial fjord, and drive heat fluxes of up to 1000 W m-2 over the Irminger Sea, with potential implications for deep water formation.